论文部分内容阅读
将Lemaitre损伤断裂准则中的单轴应力状态的线性损伤修正为多轴应力状态的非线性损伤,并以铝合金5052-O筒形件冲压实验为例,揭示了工件的等效应力、等效塑性应变和单位体积损伤值分布规律,分析了模拟和试验成形件深度和壁厚的相对误差,用于评估改进的Lemaitre损伤断裂准则在板料成形工艺中的适用性。结果表明:在使用了改进的Lemaitre损伤断裂准则的筒形件冲压模拟中,工件的等效应力和等效塑性应变的最大值都出现在圆板与凸模圆角接触的区域,且材料的单位体积损伤值达到1的区域发生了破裂。采用改进的Lemaitre损伤断裂准则预测得到的成形深度误差和壁厚最大误差分别仅为6.5%和9.2%。
The linear damage in the uniaxial stress state in the Lemaitre damage and fracture criterion is corrected to the nonlinear damage in the multiaxial stress state. The equivalent stress of the workpiece is revealed by taking the stamping experiment of the aluminum alloy 5052-O as an example Plastic strain and unit volume damage distribution, the relative errors of the depth and the wall thickness of the simulated and the test formed parts were analyzed to evaluate the applicability of the improved Lemaitre damage and fracture criterion in the sheet metal forming process. The results show that in the cylinder stamping simulation with improved Lemaitre damage and fracture criterion, the maximum equivalent stress and equivalent plastic strain of the workpiece both appear in the contact area between the circular plate and the punch, The unit volume damage value reached 1 in the area of rupture occurred. The maximum error of forming depth and wall thickness predicted by the improved Lemaitre damage and fracture criterion are only 6.5% and 9.2% respectively.